This invention relates to occupant restraint systems and more particularly to occupant restraint systems of the type which releasably secure the cushion against initial deployment normal to or toward the occupant and direct such initial deployment laterally of the occupant.
U.S. Pat. No. 5,009,452, Occupant Restraint System, issued Apr. 23, 1991 to Gregory A. Miller and assigned to the assignee of this invention, discloses an occupant restraint system which includes a reaction member mounted to the support of the restraint module and located above the inflator of an occupant restraint system. The reaction member is sealed to the upper wall portion of the occupant restraint cushion to prevent the impingement of pressure fluid from the inflator against such upper wall portion during initial deployment of the cushion and thereby restrict such initial deployment laterally of the occupant through the unfolding of the folded side and end walls of the cushion.
Copending application Ser. No. 07/752,133, Occupant Restraint System, Filed Aug. 29, 1991, Frantz et al. and assigned to the assignee of this invention, discloses a reaction member type system wherein the reaction member is mounted to the support by a flexible strap or mounting member which is looped through the reaction member and has the legs thereof secured to the support of the system. The reaction member is pocketed to the inside of the upper wall of the cushion by flaps of flexible material. In one embodiment, the flaps are individual and secured to the inside of the upper wall of the cushion. The flaps overlap each other and are sandwiched to the reaction member by a retainer member which is secured to the reaction member. In another embodiment, the flaps are part of sheet of flexible material which is provided with diagonal tear lines to separate into flaps.
The occupant restraint system of this invention is also of the type which includes a reaction member mounted to the support by a flexible strap or mounting member. However, it includes an alternate manner of sealing the interface between the reaction member and the upper wall of the occupant restraint cushion. In the preferred embodiment, a sheet of flexible material such as Tyvek, covers the reaction member and has the periphery or edge portion thereof sewn or otherwise secured to the inside of the upper wall of the folded cushion so as to seal the interface between the periphery of the reaction member and the upper wall of the cushion. The sheet of flexible material is directly secured to the reaction member in any suitable manner, such as by adhesive, and no retainer member is necessary.
The edge of the reaction member is sharpened. In one embodiment of this invention, the sheet of flexible material is perforated along a line aligned with the sharpened periphery along a line aligned with the sharpened periphery or edge of the reaction member. The sharpened edge of the reaction member cuts through the sheet of flexible material along the perforated line when the upper wall of the cushion, with the sheet of flexible material, moves away from the reaction member and normal to or toward the occupant. In another embodiment, the sheet of flexible material is not perforated, and the corners of the reaction member are arranged to initiate the cutting of the sheet of flexible material prior to the edges of the reaction member cutting the sheet of flexible material.
The primary feature of this invention is to provide an occupant restraint system which includes a reaction member mounted to a support and releasably sealed to the inside of the upper wall of the cushion during initial deployment of the cushion by a sheet of flexible material having the periphery thereof covering the periphery of the reaction member and the edge portion thereof secured to the upper wall of the cushion, with the periphery of the sheet of flexible matering being cut of severed from the remainder thereof by the reaction member and moving with the upper wall of the cushion normal to or toward the occupant during subsequent deployment of the cushion. Another feature is that the reaction member is provided with a sharpened edge to sever the periphery of the sheet of flexible material from the remainder thereof. A further feature is that the sheet of flexible material may be perforated along a line aligned with the sharpened edge of the reaction member. Yet another feature is that the corner portions of the sharpened edge of the reaction member are arranged to initiate cutting of the sheet of flexible material.